This invention relates to composite pipes, and more particularly, composite pipes suitable for advanced gas distribution systems designed to meet the diverse performance requirements of such pipes.
Much research work is presently underway to define and provide an idealized pipe suitable for use in advanced gas distribution systems. Such pipes must meet a wide variety of design requirements required by the gas utility and allied industries. An idealized pipe designed to meet these requirements should be lightweight, connectable and compatible. It should be suitable to be fabricated in long lengths of at least 1,000 feet. At the same time the pipe prior to installation should be sufficiently flexible to be wound on a drum or spool to facilitate storage and transportation to the installation site.
The idealized pipe must be locatable accurately after installation. It should have an inner layer which acts as a barrier to keep the gas within the inner lumen of the pipe. This inner layer should be smooth to reduce energy costs. The installed pipe must maintain structural integrity and permit detection of leaks through the inner layer barrier. The outer portion of the pipe need be corrosion resistant and abrasion resistant.
The principal criteria for selecting such a pipe suitable for gas distribution systems must meet the following criteria. These are:
1. provide long service life under normal use; PA1 2. be capable of tolerating damaging incidents; PA1 3. be easy to install, maintain and repair; and PA1 4. be readily manufacturable.
These criteria are defined in a draft task report entitled Preliminary Design Concepts For An Advanced Gas Distribution System prepared by Batelle Institute in Columbus, Ohio for Gas Research Institute in August, 1990. This Preliminary Design Report reviews a wide variety of design criteria and materials, such as monolithic engineering thermoplastics, toughened engineering thermoplastics, thermoplastic elastomers and a wide variety of other polymer blends. Reinforced materials are suggested as are various hybrid constructions which include a monolithic pipe in a multiple layer product. Various types of hose designs are also considered along with elastic honeycombs designs. The objective of the Report was to set forth various concepts without specifically identifying a particular construction which would be suitable.
Accordingly, it is desirable to provide a composite pipe construction, suitable for use in advanced gas distribution systems, which satisfies the criteria required for such use.